Tile grout cleaner and method of making and using the same

ABSTRACT

A cleaning tool for cleaning the walls of a swimming pool or other concrete structures. Two different sized aggregate or abrasives are combined with a binder to provide an improved cleaning device. The binder and the aggregates are matched so as to wear at substantially identical rates.

BACKGROUND OF THE INVENTION

[0001] This is a continuation-in-part of provisional application U.S.No. 60/018,980 filed on Jun. 4, 1996.

[0002] 1. Field of the Invention

[0003] This invention relates generally to cleaning devices for swimmingpools and concrete, and in particular, to a device for cleaning rustspots, calcium deposits, etc. from swimming pool walls and concrete.

[0004] 2. Description of the Related Art

[0005] In-ground swimming pools are sometimes formed of concrete, guniteor plaster (generally referred to herein as concrete). Algae stains,metal stains, and calcium scale often build up on the walls of swimmingpools. Some stains may be removed with a brush or rag, but persistentstains such as calcium scale are more difficult to remove. If theswimming pool becomes extremely stained, it is well known to drain and“acid wash” the entire pool. This typically includes scrubbing the poolwalls with a diluted mixture of muriatic acid and water and sometimesthe use of bleach. This, of course, is highly undesirable because tensof thousands of gallons of water are wasted by emptying the pool, andmuriatic acid is dangerous to work with. In addition, in-ground swimmingpools are structurally designed to be filled with water, and when theyare emptied there is a danger that the hydrostatic pressure underneaththe pool can cause the pool floor to crack.

[0006] Accordingly, there is a long-felt need in the art for a cleaningdevice for concrete swimming pools, patios, paths, driveways and otherconcrete structures that can effectively remove stains, and is easy touse and avoids the necessity of draining the pool.

SUMMARY

[0007] Accordingly, one object of the present invention is to overcomethe difficulties of the prior art.

[0008] The present invention is directed to a cleaning composition forcleaning concrete pools and other concrete devices. The compositionincludes an aggregate which is an abrasive that does the cleaning, and abinder that holds the aggregate together to be used in the cleaningprocess. The present invention achieves a balance between theperformance of the aggregate and the binder in that the aggregate andthe binder substantially uniformly break down in balance with each otherso as to efficiently use the majority or preferably substantially all ofeach layer of aggregate before the binder releases it, and a new layeris presented. The aggregate must not be harder than the material to becleaned (e.g. the pool wall) and preferably has the ability to fractureso as to continually expose new cutting or cleaning areas.

[0009] Accordingly, in one aspect of the invention the cleaning devicefor swimming pools comprises a handle, and a cleaning composite formedon the handle including (i) a polymer having an elongation at break of500%, (ii) a first type of aggregate, and (iii) a second type ofaggregate which is smaller than the first type.

[0010] Other objects, advantages and features of the invention willbecome apparent to those of ordinary skill in the art upon reading thedetailed description below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a perspective view of the cleaning tool of theinvention.

[0012]FIG. 2 is a flow chart of the method of making the cleaning toolof the invention.

[0013]FIG. 3 is a magnified view of the area within circle 3 of FIG. 1.

[0014]FIG. 4 is an exploded view of a mold for making the cleaning toolof the invention.

[0015]FIG. 5 is a side view of a second embodiment of the mold.

DETAILED DESCRIPTION

[0016] The cleaning tool of the present invention is illustrated inFIG. 1. It includes a cleaning portion 1 and a handle 2 extendingtherefrom. Handle 2 is preferably provided with a snap clip 3 forengagement in a conventional manner with a swimming pool accessoryextension pole 4.

[0017] The cleaning tool is especially useful in removing surfaceblemishes from concrete or plaster pools and ceramic tile at thewaterline of the pool. This includes cleaning the grout withoutscratching or gouging it. Such surface blemishes include rust stains,algae stains, metal stains, swimfin stains, etc. on the pool walls andcalcium build-up on ceramic tile. The cleaning composition is formed oftwo different sized aggregates used as the cleaning or abrasive elementof the device and a selected polymer, described more fully below, whichtool posts or encases each aggregate particle. As shown in FIG. 3, twodifferent sizes of aggregates are used so that smaller aggregates 6 nestwithin the spaces between larger aggregates 5. This results in a denserpacked concentration of the aggregate which improves results.

[0018] In developing the present invention, the inventor experimentedwith numerous types of binders (polymers) and aggregates. Each failed toachieve the superior and unexpected results of the present invention.

[0019] Different types of aggregates that were experimented withinclude: crushed walnut shells, which tended to be too tough, crushedcorn cobs which were too soft, and crushed peach pits which also weretoo soft. Silicon carbide was used, but it was too hard and sharp, aswas aluminum oxide. A powdered detergent was tried, but that had noteffect, as did sawdust and cloth. Garnet was too sharp, tungsten carbidewas too hard, and pumice was too soft.

[0020] The use of silica sand as the aggregate achieved the best resultsfor providing the proper hardness and wearability for concrete.

[0021] In addition, experiments were performed with numerous binders.These include a two-part polyurethane casting system having a shore Ahardness of 50-60 sold by Hexcel Corporation of California. However, theinventor found that the more suitable binder to achieve the desiredbalance with the silica sand was a mold compound marketed by Smooth OnCorporation located in Gillette, N.J. known as PMC-121 having a shore Ahardness of 50. Although uncertain, the inventor believes that thisproduct achieves superior results because of its elongation at breakproperty of 500%. However, other properties, or combinations ofproperties of the binder may be the reason why the superior results areachieved. The Smooth On PMC-121 product has the following properties. Aviscosity of 1,400 cps, a specific gravity of 1.04 g/cm³, a specificvolume of 26.7 cubic inches per pound, Utimate tensile strength of 350PSI, a shore A hardness of 50, a compression set of 16.5%, a 100%modulus of 100 PSI, and a tear strength of 65 PLI.

[0022] The materials selected for use in the present invention work incombination such that the binder which holds the aggregate materialwears at substantially the same rate as the aggregate. Thus, as theaggregate wears down and loses its cleaning ability, the binder alsowears down until the spent aggregate and binder fall off the device. Asa result, a new layer of aggregate and binder are exposed to, provide anew cleaning surface. As shown in FIG. 3, the use of two sizedaggregates, silica sand #20 and silica sand #30, work together such thatthe smaller silica sand 6 nestles into the spaces between adjacentlarger particles of silica sand 5. The sand is also surrounded by thepolymer 7. Moreover, silica sand is friable and therefore continuallypresents new cutting or cleaning edges to be used in cleaning the poolwall. The above advantages are achieved, in one aspect of the invention,by the following composition.

[0023] A composition of matter including the following elements inpercentages by volume: 40% of a polymer having a 50 shore A hardness andan elongation at break of 500%, such as PMC 121/50 marketed by Smooth-OnCorporation of Gillette, N.J. 5% MEK (methyl ethyl ketone), 27½% silicasand no. 20 and 27½% silica sand no. 30.

[0024]FIG. 2 illustrates a method of making the cleaning tool of theinvention. As Smooth-On PMC 121 is a two-part polymer, there is a part Aand a part B which must be mixed together to form the product. Typicallythis is done in a pail with plastic spatula. In step 10, part A and partB are mixed at a 1:1 ratio for approximately 1 minute to constitute 40%of the entire volume to be made. Next, in step 20, MEK is added to themix to constitute 5% of the volume of material to be made and the mix iscontinued to be mixed for another minute to two minutes. In step 30,27½% silica sand no. 20 and 27½% silica sand no. 30 are added and themixture is again mixed for a minute or two minutes. In step 40 themixture is poured into a mold and allowed to set for 4-6 hours at roomtemperature. The mold is then released (step 50) and the product allowedto cure for an additional six or seven days (step 60).

[0025]FIG. 4 illustrates a mold 70 for use with the invention. As shown,the mold 70 has two parts 72 and 74 which join together when thecomposition is poured. Each part 72 and 74 have cut-outs 76 formedtherein to form the shape of the molded tool. The top of each part ofthe mold 70 also has a semi-circle 80 a or 80 b formed therein such thatwhen parts 72 and 74 are joined together semi-circles 80 a and 80 b forma full circle 82. The mold is then poured through the circle 82 andhandle 2 is then inserted through the circle 82 into the mold. The moldis released by separating the two parts 72 and 74 of the mold 70.

[0026]FIG. 5 shows an alternate embodiment of the mold 70′ in whichmultiple molds are stacked upon each other.

[0027] Having thereby described certain embodiments of the invention, itwill be apparent to those skilled in the art that many modifications maybe made within the scope of the invention. Therefore, the scope of theinvention is only limited by the appended claims.

[0028] For example, in certain embodiments of the invention, titaniumdioxide may be added to the mix in a small amount to suitably color thefinal product.

What is claimed is:
 1. A cleaning device for swimming pools comprising:a handle; and a cleaning composite formed on the handle including (i) apolymer having an elongation at break of 500%, (ii) a first type ofaggregate, and (iii) a second type of aggregate which is smaller thanthe first type.
 2. The claimed device of claim 1 , wherein said polymeris Smooth-On PMC 121/50.
 3. The claimed device of claim 1 , wherein thefirst type of aggregate is silica sand no. 30 and the second type ofaggregate is silica sand no.
 20. 4. The claimed device of claim 1 ,wherein the first type of aggregate is friable and the second type ofaggregate is friable.
 5. A cleaning composition comprising: a first typeof aggregate which is friable; a second type of aggregate which isfriable; a binder for binding the first and second types of aggregatetogether; wherein upon the cleaning composition being scrubbed against aconcrete structure, the first and second type of aggregate and thebinder all wear at substantially the same rate.
 6. The cleaningcomposition of claim 5 , wherein the first type of aggregate is silicasand no. 20 and the second type of aggregate is silica sand no.
 30. 7.The cleaning composition of claim 5 , wherein the binder is a polymerhaving an elongation to break of 500%, a tensile strength of 350 PSI andshore A hardness of
 50. 8. The cleaning composition of claim 5 , furthercomprising a polymer thinner.
 9. The cleaning composition of claim 8 ,wherein the polymer thinner if methyl ethyl ketone.
 10. A cleaningcomposition for cleaning swimming pool walls, consisting essentially of:about 40% by volume of a polymer having an elongation to break of 500%,a tensile strength of 350 PSI and a shore A hardness of 50; about 5% byvolume of a polymer thinner; about 55% by volume of an aggregate whichis friable.
 11. The cleaning composition of claim 10 , wherein theaggregate comprises a 1:1 mix of silica sand no. 20 and silica sand no.30.
 12. The cleaning composition of claim 10 , wherein the polymerthinner is methyl ethyl ketone.
 13. The cleaning composition of claim 10, wherein the polymer is Smooth-On PMC-121/50.
 14. A method of making acleaning device for cleaning swimming pool walls, comprising: mixing atwo part polymer composition having a 50 shore A hardness and 500%elongation at break in a 1:1 ratio; mixing a polymer thinner with thepolymer; adding an aggregate comprising 50% silica sand 20 and 50%silica sand 30 to the mixture; molding said mixture for a firstpredetermined time; and curing the molded mixture for a secondpredetermined time.
 15. The method of claim 14 , wherein said firstpredetermined time is 4-6 hours.
 16. The method of claim 14 , whereinsaid second predetermined time is 6-7 days.
 17. The method of claim 14 ,wherein said polymer thinner is MEK.
 18. The method of claim 14 ,wherein said two part polymer composition is SMOOTH-ON PMC-121/50. 19.The method of claim 14 , further comprising adding titanium dioxide tothe mixture.